The invention relates to a tool exchanging apparatus for a processing center.
A known tool exchanging apparatus of this type (DE 40 09 537 C2) is provided with a tool exchange stand, which is movable in the linear direction between a magazine delivery position and a spindle delivery position. The tool-exchanging stand carries a gripping equipment provided with two gripping devices which can be rotated around an axis to move them between the horizontal and the vertical position. In the spindle delivery position, the used tool is delivered from the tool spindle of the processing machine to one of the gripping devices and a new tool is removed from the second gripping device. In addition to the pivot drive for the gripping devices and the transport drive for the tool exchanging stand, the tool exchanging apparatus also requires a driving mechanism for opening and closing of the gripping devices. Such a large number of driving mechanisms means that this apparatus is expensive. The tools of this known apparatus must be switched between the magazine and the tool-exchanging stand by means of another independently manipulated device. The transport of the tool including the preparation in the magazine, the delivery to the manipulating device, and a further delivery to the exchange stand and transport to the spindle delivery position which includes also rotation of the gripping devices requires so much time that this time period will exceed the time period during which the tool is used when the processing center is operated at a high speed. The utilization level of the processing machine is thus adversely affected because the machine must wait for the next tool.
Also, a sheet metal processing machine provided with a tool magazine is known (from DE 37 01 858 A1), which enables tool-receiving operations. The tools are inserted from the tool magazine with a delivering mechanism in a transporting mechanism and removed again from this transporting mechanism after the tools have been used. The transporting mechanism transports the tool from a mounting position to the processing position. As soon as the processing is finished, the used tool is moved from the processing position to a removing position, while a new tool, which is supplied in advance from the magazine to the transporting mechanism, travels to the processing position. A similar construction is suitable only for machines deployed in stationary processing positions. Moreover, a similar apparatus does not permit a particularly quick access to a plurality of different tools when all of these tools need to be exchanged quickly.
Also known is a tool exchanging apparatus provided with two tool spindles (JP 03 010736 A), according to which each tool spindles is always assigned only to one tool holding device.
Each tool holding device must be equipped with an additional delivery device, which is constructed as a rocking lever and which must be also emptied. The delivery devices constructed as rocking levers remove the tools from the circulating tool magazine and they deposit the tools into the circulating tool magazine.
This known tool exchanging apparatus can be only used if it is equipped with two tool spindles. An economical exchange of tools thus cannot be achieved with the help of this apparatus since one of the tool spindles will always remain unused.
Based on the status of technology, the objective if this invention is to create a simple tool exchanging apparatus which makes it possible to realize the shortest possible tool transporting time even when there is a great number of tool locations.
The solution or this task is accomplished in accordance with the embodiments discussed below.
According to one embodiment, simple movements will occur between the preparing position for a new tool or the receiving position for a used tool of the tool magazine and the tool changing position, movements that can take places independently of each other, both with respect to the used tool and with respect to the new tool. The replacement of the tools saves time as it occurs when the tools are in neighboring positions, and the exchange is conducted in an inexpensive manner by using for this purpose the movements of the machine without causing waiting time periods by the movements of the magazine.
Preferred embodiments of the invention will become clear from the subordinated claims.